An iontophoretic structure for medical devices is provided that uses controlled electrical current derived from two dissimilar galvanic materials to drive oligodynamic metal ions into solution to kill bacteria on and near the device to which the structure is affixed. In one embodiment, a first galvanic material separated from a second galvanic material by a resistive material produces an anti-bacterial current flow when placed in contact with an electrolytic fluid. In another embodiment, a cylindrical elastomeric catheter incorporates a first and a second galvanic material separated by a resistive material which controls a current flow between the galvanic materials when the catheter is immersed in an electrolytic fluid. The galvanic materials can be dissimilar metal powders embedded in a conductive polymer substrate that forms an iontophoretic composite material, or dissimilar metals arranged in layers separated by a resistive layer. In yet another embodiment, the iontophoretic composite material is configured as an infection control sleeve that covers a portion of an ordinary catheter or cannula. Methods of protecting implantable medical devices and body structures with the iontophoretic structures are also provided.